In nowadays people's life, video transmission technology such as video chat has been widely used. However, during video transmissions, a phenomenon called visual sense inequality is prone to occur in a video communication of two parties due to a difference in viewing positions of cameras. For example, when people are chatting, their eyes are looking at a display screen, but the viewing position of a camera is usually at one side of the display screen, therefore, the other party's image seen by one is not looking at oneself all the time, thus degrading sensory experience.